(a) Field of the Invention
The invention relates to a transceiver device, particularly to a transceiver device to lower interference that causes an packet error in a communication system.
(b) Description of the Related Art
In a traditional Fast Ethernet system, although it is a full-duplex system, transmitting and receiving (Tx/Rx) are divided into two transmission paths for the same receiving end and they do not interfere with each other. Therefore, when two ends are not under the state of transmitting packets, the same idle sequence will be outputted. Since a fast Ethernet system comprises two different transmission paths, there is no influence even when the same signals are outputted.
At first, in a Fast Ethernet environment, since the starting point in the original design is transmission of two transmission paths (each is unidirectional), the same MLT-3 idle sequence is outputted when two ends are not under the state of transmitting packets and the same signals are outputted by the two ends within a short period of time because the frequencies of the two ends are different. Such a situation happens periodically and the occurrence period of the situation depends on frequency drifting of the two ends.
The high definition multimedia interface (HDMI) application uses a transmission path to execute bidirectional transmission, receiving not only signals from two ends but also echo signals from their own output. When the signals outputted by the two ends are the same, that is, the signal from the other end is the same as the echo signal, the receiving end becomes having a better signal-to-noise ratio because of increased amount of received energy to make the convergence parameter of the receiving end converged to an incorrect solution. If the other end is executing the packet transmission at the time, it will result in an packet error due to the incorrect convergence parameter.
Besides, in a Gigabit Ethernet system, transmitting and receiving should be executed in the same transmission path but the MLT-3 idle sequence outputted by the two ends are different because the above problem is considered during establishing the specification and thus the signals are not mixed up.
However, in the specification of HDMI 1.4 using Fast Ethernet specification, due to limitation of transmission media, transmitting and receiving are set to execute transmission in the same transmission path. Because Fast Ethernet specification originally has no application executing transmission in the same transmission path, the above mentioned situation are not considered and packet errors happen so that the system can fail easily.